In envelope manufacturing, processing and handling operations it may be desired to move relatively large numbers of envelopes in a rapid manner. In particular it is often desired to lift and move discreet stacks of envelopes. In order to lift and move a stack of envelopes the stack may be gripped between a pair of opposed arms and then lifted and moved.
However, the number of envelopes that can be lifted in this manner is limited. More particularly, envelopes typically have a greater thickness or a greater number of plies at certain portions (i.e. the center of the envelope) as compared to other (i.e. outer) portions of the envelope. Thus when a relatively large number of envelopes are gripped and pressed together the greater thickness at the center of the envelopes limits the compression forces that can be applied to the outer edges of the envelope, which results in an unstable gripped stack. This phenomenon can be replicated when a person attempts to grip a large number of envelopes (i.e. an envelope stack one or several feet long) between the person's arms, and the gripped stack bows outwardly until the envelopes spray apart. Accordingly, there is a need for an improved apparatus and method for gripping and moving stacks of envelopes.